Drive for a tire lift mechanism and method for assembling same

ABSTRACT

An improved tire lift mechanism is disclosed in which a drive tube selectively rotates a driven shaft to raise and lower a cable fixed to a spare tire. The drive tube is connected to the driven shaft through a connection formed of a plurality of circumferentially-spaced pins which are received within notches in the driven shaft. Spaces are provided between the drive pins. Liquids in the area of the connection drain outwardly of the spaces and do not freeze in the area, which could prevent use of the tire lift mechanism. A spring is disposed between the driven shaft and the drive tube to eliminate looseness, and resultant rattling. Finally, a method of assembling the tire lift mechanism is disclosed in which the drive tube is formed of a pair of telescopic tube members. The members are telescopically moved relative to each other to a collapsed position, and the mechanism is fixed to the underside of a vehicle. The tube members are then telescopically moved to an expanded position with the tube moving through a bearing member to mount the tire lift mechanism to the underside of a vehicle. This reduces the complexity of assembling the tire lift mechanism over prior art assemblies.

BACKGROUND OF THE INVENTION

This application relates in general to an improved drive for a tire liftmechanism, and also to a simplified method of assembling suchmechanisms.

It is known to store a spare tire at the underside of a vehicle,particularly in vans. Tire lift mechanisms are typically utilized forraising and lowering the spare tire from beneath the vehicle. A cableextends from the lift mechanism and a rotative drive is arranged upon afirst axis for lowering and raising the cable, to raise and lower thespare tire. An access opening may be formed through the rear of thevehicle body, and a tool such as a jack handle may be inserted throughthe access opening and used to raise and lower the cable.

One particularly successful example of such a mechanism is disclosed inU.S. Pat. No. 4,915,358. A drive tube is selectively driven by a toolfor raising and lowering a cable. The drive tube is rotatably receivedin a bearing formed beneath the underside of a vehicle, and drives adriven shaft, which is connected to the actual drive for the cable. Theconnection between the drive tube and the driven shaft is auniversal-type connection wherein the drive tube has a plurality ofcircumferentially-shaped drive pins received in slots in the drivenshaft. The drive pins may pivot relative to the slots such that the axisof rotation of the drive tube may be at an angle relative to the axis ofrotation of the driven shaft. This facilitates the use of the assembly,such that a user need not bend to a low vertical position to raise andlower the tire.

Although the above-discussed patented mechanism has proven successful,several improvements may still be made. The universal connection of thedrive tube to the driven shaft includes a radially outwardly disposedcup. This cup may retain water, which may freeze, locking theconnection. Further, the connection between the drive tube and thedriven shaft may result in undesirable rattling and looseness. Lastly,it is somewhat difficult to mount the tire lift mechanism to theunderside of a vehicle, and then position the drive tube through itsbearing mount. These three area are improved in the present invention.

SUMMARY OF THE INVENTION

In a disclosed embodiment of the present invention, a drive tube isconnected to a driven shaft through a universal connection whichincludes a number of drive pins fixed to the drive tube, and received innotches in the driven shaft. The pins may pivot within the notches, butstill transmit drive. The universal connection includes spaces betweenthe drive pins which extend radially outwardly of the connection. Watermay drain outwardly through these spaces.

The drive tube also includes plates spaced on each axial side of adriven shaft plate which includes the notches. The drive pins extendbetween the drive tube plates. A spring is positioned between the drivenshaft plate and one of the plates from the drive tube. This springensures that the drive tube is biased towards the driven shaft,eliminating rattling and undesirable looseness in any relative angularposition.

In a final feature of the present invention, a unique tool is disclosedfor initially assembling the tire lift mechanism. The drive tubeconsists of a pair of telescopic tube portions which may slide relativeto each other. To assemble the tire lift mechanism to a vehicle, themechanism is first attached to the underside of the vehicle. At thattime, the drive tube portions are telescope upon each other to acollapsed position. The unique tool is inserted into the drive tube, andone tube portion slides telescopically relative to the other. The onetube portion is pulled through a bearing mount. This simplifies theassembly of the tire lift mechanism of the present invention.

Further objects and features of the present invention can be bestunderstood from the following specification and drawings, of which thefollowing is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the underside of a vehicle including theinventive tire lift mechanism.

FIG. 2 is a largely schematic cross-sectional view of the inventive tirelift mechanism.

FIG. 3 is a cross-sectional view through the tire lift mechanism shownin FIG. 2.

FIG. 4 is a plan view of the tire lift mechanism illustrated in FIG. 3.

FIG. 5 is a cross-sectional view along line 5--5 as shown in FIG. 4.

FIG. 6 is a cross-sectional view along line 6--6 as shown in FIG. 4.

FIG. 7 is a cross-sectional view along line 7--7 as shown in FIG. 4.

FIG. 8 is a view of a tool for assembling the tire lift mechanism of thepresent invention.

FIG. 9 illustrates the first step in assembling the tire lift mechanismof the present invention to a vehicle.

FIG. 10 is a cross-sectional view along line 10--10 as shown in FIG. 9.

FIG. 11 illustrates a subsequent step in the assembly of the tire liftmechanism.

FIG. 12 is a cross-sectional view along line 12--12 as shown in FIG. 11.

FIG. 13 shows the final assembly of the tire lift mechanism.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 illustrates tire lift mechanism 20 for raising and lowering sparetire 22 from beneath the underside 24 of a vehicle. Bracket 26 mounts anassembly 28 which includes known structure for raising and loweringcable 27. Cable 27 is fixed to member 29 which is received in theopening on spare tire 22.

A manual drive assembly 30 for selectively driving assembly 28 to raiseand lower cable 27 will be disclosed below. The details of the drivewithin assembly 28 may be similar to that disclosed in U.S. Pat. No.4,915,358, the disclosure of which is hereby incorporated by reference.It should be understood, however, that the details of the drive withinassembly 28 form no part of this invention, and thus any type of drivemay be utilized for raising and lowering cable 27.

FIG. 2 is a largely schematic cross-sectional view illustrating featuresof tire lift mechanism 20. Member 29 retains tire 22 beneath vehiclebody 24. Bracket 26 mounts assembly 28 for raising and lowering cable27. Drive assembly 30 includes drive tube 32 which selectively drivesdriven shaft 34. Driven shaft 34 drives structure within assembly 28 toraise and lower cable 27.

Drive tube 32 consists of a first inner tube portion 36 and a secondouter tube portion 38. Outer tube portion 38 is rotatably receivedwithin bearing 40 on vehicle underside 24, and rotates with inner tube36. Outer tube 38 may slide telescopically on inner tube 36.

An access opening 41 is formed in the rear of the vehicle. A tool, suchas a jack handle 42 may be inserted through opening 41 and into outertube 38 and may be used to rotate outer tube 38 and inner tube 36, whichin turn rotates driven shaft 34. Other tools, such as a lug wrench maybe used. Driven shaft 34 raises and lowers cable 27 to raise and lowerspare tire 22.

As shown in FIG. 3, tool 42 includes a first tapered end 46 which isreceived within a drive connection 44 in inner tube 36. Outer tube 38has lip 43 which snaps into notch 45 ill inner tube 36 , locking the twotogether and preventing any further telescopic movement. A forward endof outer tube 38 is angled outwardly 47 to facilitate sliding of outertube 38 on inner tube 36.

Inner tube 36 includes plug 48 which is fixed to first plate 50. Aplurality of drive pins 56 connect plates 50 and 51, which are on spacedaxial sides of plate 57 associated with driven shaft 34. Plate 57includes a plurality of notches 58 which pivotably receive drive pins56. Bearing 52 is pivotally received within a central portion of drivenshaft 54. Driven shaft 54 includes sleeve member 60 received on shaft62, which is connected to drive structure within assembly 28.

If drive tube 32 is pivoted with respect to driven shaft 34, drive pins56 pivot in notches 50. When drive tube 32, and thus drive pins 56 arerotated, notches 58 and thus plate 57 rotate, which rotates shaft 62 toraise and lower cable 27. Spaces are formed circumferentially betweendrive pins 56 to allow leakage of water outwardly of the connection.

Coil spring 64 biases plate 50 towards plate 57. This eliminateslooseness and rattling between drive tube 32 and driven shaft 34.

FIG. 4 is a plan view of drive assembly 30 prior to assembly. Outer tube38 and inner tube 36 are telescopically received on each other in acollapsed position. Plates 50 and 51 are on spaced axial sides of plate57. Drive tube 32 and driven shaft 34 extend coaxially. Drive pins 56are received within notches 58 in plate 57. Spring 64 biases plate 50against plate 57.

FIG. 5 is a cross-sectional view along line 5--5 as shown in FIG. 4. Asshown, plate 57 includes a plurality of notches 58 receiving a pluralityof drive pins 56. Drive pins 56 may pivot in notches 58 and stilltransmit rotation.

FIG. 6 is a view along line 6--6 as shown in FIG. 4. Drive structure 44is generally rectangular, and receives the pointed end of a jack handle.

FIG. 7 is a cross-sectional view along line 7--7, and shows structure,which will be described below, to facilitate assembly of mechanism 20 tothe underside of a vehicle 24. As shown, outer tube 38 includes elongatesplit 64. Split 64 facilitates the sliding movement of outer tube 38 oninner tube 36. A pair of radial inwardly extending ears 66 are formed inouter tube 38. One extends across split 64. The inner periphery of outertube 38 is generally cylindrical, other than at the location of ears 66.Ears 66 are spaced 180° from each other.

FIG. 8 is a view of tool 70 for facilitating the assembly of mechanism20 to underside 24 of a vehicle. Tool 70 consists of lock portion 72,received between forward end 74 and rearward end 76. Lock portion 72 hasa cross-section somewhat similar to the cross-section of forward end 74adjacent lock portion 72. There is one difference, which will bedescribed below. Rearward end 76 has a larger diameter than lock portion72. Handle 78 is disposed at an opposed end of the tool. A threaded bolt75 extends through sleeve 77 and threadably receives rearward end 76,lock portion 72 and forward end 74. A threaded plastic member 79 mayalso be positioned on bolt 75. The use of plastic members 74, 77 and 79prevents damage to mechanism 20. Preferably, the plastic portions oftool 70, including portions 74 and 79 are formed from a materialavailable under the tradename Derlon™. Sleeve 77 is preferably formed ofa suitable Nylon.

As shown in FIG. 9, mechanism 20 is first attached to bracket 26. Outertube 38 is telescopically received on inner tube 36 at a collapsedposition. In the past, it has been difficult to mount mechanism 20 tothe underside of a vehicle 24, and also position the drive tube withinbearing 40. As shown, when mechanism 20 is initially mounted to bracket26, the outer end of outer tube 38 is not received within bearing 40.

Tool 70 is inserted into the outer end of outer tube 38 until lockportion 72 is axially aligned with ears 66. Rearward end 76, which has agreater outer diameter than lock portion 66 or forward end 74, abutsears 66 stopping further forward movement of tool 70 into outer tube 38and defining this axial position.

FIG. 10 is a cross-sectional view through line 10--10, and shows lockportion 72 aligned with ears 66. Lock portion 72 has a pair of opposedflats 80 which are circumferentially and axially aligned with ears 66.When initially inserting tool 70 one ensures the circumferentialalignment of flats 80 with ears 66. Curved lock portions 82 connectflats 80. Forward end 24 has approximately the same cross-section aslock portion 72, but has curved portions 83 with a diameter greater thancurved portions 82. When in this initial position, curved portions 82and 83 are aligned with the curved inner periphery portion 68 of outertube 38. Curved portions 83 are positioned axially beyond ears 66.

As shown in FIG. 11, tool 70 is rotated. As shown in FIG. 12, once tool70 is rotated, curved portions 82 and 83 are now circumferentiallyaligned with ears 66. Curved portions 83 which are of greater diameterthan curved portions 82 now prevent removal of tool 70 from outer tube38 since they abut ears 66. Tool 70 is pulled outwardly and curvedportions 83 pull ears 66 outwardly such that outer tube 38 slides oninner tube 36.

Outer tube is pulled outwardly through bearing 40, and is then rotatablyreceived in bearing 40. Mechanism 20 is now in a position such as isillustrated in FIG. 3, and is fully assembled. As shown in FIG. 13, lip43 snaps into notch 45 and outer tube is locked relative to inner tube36. Tool 70 is then rotated and removed.

The metal portions of the assembly are preferably formed of sinteredpowder metals. This increases the strength over prior art assemblies.

A preferred embodiment of the present invention has been disclosed,however, a worker of ordinary skill in the art would recognize thatcertain modifications would come within the scope of this invention. Forthat reason the following claims should be studied in order to determinethe true scope and content of this invention.

I claim:
 1. A tire lift mechanism comprising:a cable; a drive tubeadapted t be selectively rotated to cause said cable to be raised andlowered; a driven shaft adapted to rotate structure for raising andlowering said cable, said driven shaft being selectively driven by saiddrive tube, said drive tube and said driven shaft being operablyconnected by a connection such that an axis of rotation of said drivetube may be non-parallel to an axis of rotation of said driven shaft,said connection including drainage spaces such that any fluids in thearea of said connection may drain radially outwardly of said connection;said drive tube including a plurality of circumferentially-spaced drivepins, said driven shaft including a plate having a plurality of notchesat a radially outward position, said notches receiving said drive pinssuch that said drive pins may pivot within said notches but stilltransmit rotation, said drainage spaces being defined between said drivepins and extending radially outwardly of said connection such thatfluids received in the area of said drive pins and said notices maydrain outwardly; and said drive pins are fixed in a first drive tubeplate which is fixed to said drive tube, and a spring is disposedbetween said driven shaft plate, and said first drive tube plate, saidspring surrounding said driven shaft, said spring eliminating rattling.2. A tire lift mechanism as recited in claim 1, wherein there is asecond drive tube plate, said first and second drive tube plates beingspaced on opposed axial sides of said driven shaft plate, said drivetube extending axially away from said driven shaft on one axial side ofsaid driven shaft plate, and said spring and said first drive tube platebeing on a second axial side of said driven shaft plate.
 3. A tire liftmechanism as recited in claim 2, wherein there are a plurality ofcircumferentially-spaced drive pins which connect said first and seconddrive tube plates, said notches receiving said drive pins such that saiddrive pins may pivot within said notches, but still transmit rotation.4. A tire lift mechanism comprising:a cable; a drive tube adapted to beselectively rotated to cause said cable to be raised and lowered; adriven shaft and structure for raising and lowering said cable, saiddriven shaft adapted for rotation of said structure for raising andlowering said cable, said driven shaft being selectively driven by saiddrive tube, said drive tube and said driven shaft being operablyconnected by a connection such that an axis of rotation of said drivetube may be non-parallel to an axis of rotation of said driven shaft;and said drive tube includes an outer tube portion and an inner tubeportion, said tube portions being telescopically received upon eachother, said outer tube portion being mounted within a bearing on theunderside of a vehicle.
 5. A tire lift mechanism as recited in claim 4,wherein said outer tube portion includes an axial slot extending along afirst circumferential position, and facilitating the sliding movement ofsaid outer tube portion on said inner tube portion.
 6. A tire liftmechanism as recited in claim 5, wherein at least a first ear is formedin said outer tube portion, said ear extending radially inwardly from agenerally cylindrical inner periphery of said outer tube portion.
 7. Atire lift mechanism comprising:a cable and a drive tube adapted to beselectively rotated to cause said cable to be raised and lowered; and adriven shaft and structure for raising and lowering said cable, saiddriven shaft adapted for rotation of said structure for raising andlowering said cable, said driven shaft being selectively driven by saiddrive tube, said drive tube and said driven shaft being operablyconnected by a connection such that an axis of rotation of said drivetube may be non-parallel to an axis of rotation of said driven shaft,said connection of said drive tube to said drive shaft including atleast a first plate which is fixed to said drive tube, said driven shaftincluding a driven shaft plate, a spring disposed between said first anddriven shaft plates and surrounding said driven shaft to bias saidplates towards each other.
 8. A tire lift mechanism as recited in claim7, wherein there is a second drive tube plate, said first and seconddrive tube plates being spaced on opposed axial sides of said drivenshaft plate, said drive tube extending axially away from said drivenshaft on one axial side of said driven shaft plate, and said spring andsaid first drive tube plate being on a second axial side of said drivenshaft plate.
 9. A tire lift mechanism as recited in claim 8, wherein aplurality of circumferentially-spaced drive pins connect said first andsecond drive tube plates, said driven shaft plate having a plurality ofnotches at a radially outward position for receiving said drive pinssuch that said drive pins may pivot within said notches, but stilltransmit rotation.
 10. A tire lift mechanism as recited in claim 7,wherein a plurality of circumferentially spaced drive pins are fixed tosaid first plate, said driven shaft plate including a plurality ofnotches at a radially outward position, said notches receiving saiddrive pins such that said drive pins may pivot within said notches, butstill transmit rotation.